Hydraulic brake system



e. FORNACA HYDRAULIC BRAKE SYSTEM Original iled Feb. 27''. 1923 2 Sheets-Sheet 1 Feb. 2 1926.

G. FORNACA HYDRAULIC BRAKE SYSTEM origih'al Filed Feb. 27-, 1923 2 Sheets-Sheet 2 3141x2711 of, I I ,za'da fr/maa Patented Feb. 2, 1926.

UNITED STATES 1,511,517 PATENT OFFICE.

GUIDO FORNACA, OF TURIN, ITALY.

HYDRAULIC BRAKE SYSTEM.

Original application filed February 27, 1923, Serial No,-621, 670. Divided and this application filed. Iarch e, 1924. Serial No. 697,368.

To all whom it may concern:

Be it known that I, GUmo FonNAoA, a subject of the King of Italy, residing at 7,

'via Giann'one, Turin, in the Kingdom of Italy, have invented certain new and useful Improvements in Hydraulic Brake Systems, of which the following is a specification.

This'invention relates to improvements 1n hydraulic brake systems for motor vehicles as described in my co-pending application Serial No. 621,670 filed' F ebruary'27th, 1923,

of'which. the present case is a division. Ac-

cording to the invention a single cylinder is provided for automatically operating all the brakes which are connected together by a systemof levers and differential gearings, allowing compensation between the front and rear brake groups and also between the front and rear brakes themselves.

According to t-he'invention means are further provided for completing the action of the hydraulic system by means of the usual hand and pedal operating arrangements, Whichactuate allor part of the brakes.

The accompanying drawing shows, by

way of example, a constructional form of* the hydraulic brake system according to this invention. 1 I i Figure 1 a perspective view of the frame of amotor vehicle, on which are mounted the hydraulic-brake system and the hand and pedal operating devices.

\ Figure 2 is a detail view partly in section, showing the c'ountershafts, which are enclosing the pump, the cylinder and the valves.

' In. Figure 1. 1 denotes the frame of the 'motor vehicle, 2 and 2 are the drums of the front brakes, 3 and 3' the operating arrangements, and 4 and 4 the rods thereof.

'T' .2 drums of the rear brakes, with their operating arrangements and rods, are de-' noted by 5 and 5, 6 and 6, 7 and 7', respectively.

rod 9 described in my. co-pending application above identified) which is connected in The (pedal8 is connected with the resilientits turn with the lever l0 for a tuating the valve of the hydraulic brake echanism situated within the casing 11, the latter being secured to the cross bar 12 of the frame.

The piston rod 14 of the hydraulic bi'aking gear projects from the casing 11 and is connected to a lever 15, keyed on to. a cross shaft 16, on which are loosely mounted sleeves 17 and 18 having toothed sectors 17 and 18, respectively in gear witha pinion 19 pivotally carried by a lever 20, keyed on the shaft 16. a i

' The sleeve 18 carries a lever 21, connected by a two-part.rod with a lever 23 secured to a sleeve 23 and having mounted on it a latter together with the bevel pinion v 29,

serving to operate toothed sectors 30' and 31 attached to the sleeves 30, 31 mounted on a cross shaft and connected by levers 30" and 31" and rods 4, ,4 with the operating arran ements 3, 3' for the front brakes.

The difierential gearing 19, 17, 18' constitutes a compensating system between-the front brakes and the rear brakes, whilst'the differential gear-ings 24, 25),26' and 29,- 30', 31 constitute compensating systems between the two rear brakes and between the two front brakes, respectively.

The pedal 8 is secured to the shaft 8' and acts on the lever 20 through a lever'8 on the shaft.

The'two-part rod above-mentioned comprises sections22'and 22 carrying slides 32 and 32' at their mutually-adjacent inner ends, between which slides engages the pivot' 33' ofa forked lever 33, connected to the i hand-lever 35 through the medium of the 100 with their levers are mounted ina box 50 which may be the gear box of the vehicle.

Figure 3 shows besides the members 8, 15, 105

9, 14, illustrated in the preceding figures, a section of the brake." cylinder 39 with the corresponding piston 40 and control valve 38 actuated through the medium of the lever 10 and rod 9 from the pedal 8.

bevel pinion 24, whichgears with toothed Figure shows the essential parts of the hydraulic operating device, namely the pump 42, cylinder 39, controlling valve 38, safety Valve 41 and operating lever 10. The worklever 15.

ing of this arrangement is described in my co-pending application.

The working of the arrangement illustrated is as follows:

By putting pressure on the pedal 8 the lever 10 is moved to close the valve 38 more or less completely according to the pressure exerted by the foot. Oilis then delivered by the pump 42 into thefcylinder 39 and moves the piston 40, thereby moving the rod 14 and turning the shaft 16 by means of the The movement of the shaft 16 causes a corresponding movement of the pinion 19, which, in its turn, actuates the lever 21, the two-part rod 22*22' and the lever 23, whilst through its differential 'gearing it also works the levers 25" and 26" connected to the rods 7 7"- of the rear brakes. At the same time the lever, 27 is ac-' tuated and moves the lever 28 which, acting through its difierential gearing 29, 30', 31', moves the levers 30" and 31" connected to the front brakes by the rods 4, 4'.

Thus by the single movement of the piston 40 the four brakes are put into operation simultaneously through automatically acting compensating means. The same effeet can be obtained independently of the, hydraulic arrangement, by increasing the; pressure of the foot on the pedal, so as to. apply the muscular power of the'driver to the brakes and to close the valve 38. The lever 8" is then pressed against the lever 20, and the bevel pinion 19 operates simultaneously the-rear brakes and the front brakes, through the sleeves 17 and 18.

When the two-part rod 22. 22 for work-" ing the rear brakes is put into action the hand lever '35 does not leaveits position of rest forthe slide 32, which forms part of the rod, has no influence on the'forked lever 33. On the other hand the brakescan be.

ut on by actuating the hand lever when the ever;,33, on the front end of the slide, will be pushed forward producingthe same-effeet on the two-part rod as though the rod were operated by the hydraulic arrangement or by. the pedal. .In this case the braking effect is exerted only onthe rear wheels, -be cause the part 32 of the slide allows a forward movement of the part 32' and of the rear member'of the two part' rod independently of the front part of the rod, and consequent] without the lever 21 being influenced y the action of the hand lever 35. I claim as my invention: v

1. In a four-wheel brake system for motor 7 cars, the combination, with the front and rear wheels and their individual brakes; of

h draulic mechanism embodying a single p ston and cylinder only; front and rear transversely-arranged rock shafts a {mind brake-operating rods connecting each shaft and the correspondingpair of brakes; and

connections between the hydraulic mechan sm and both shafts for actuating the latter simultaneously from t e former, and to which the single piston of said mechanism is operatively related.

2. .In a four-wheeLbrake system for motor cars, the combination,,with the front. and rear Wheels and theirindividual brakes; of hydraulic mechanism embodying asingle piston and cylinder only; a pair'of'operating rods for each pairof brakes; and a system of compensating members comprising differential mechanisms connecting the hydraulic mechanism with both pairs of rods .for ac .tuating the latter simultaneously from the former, 'and to which the single piston of said mechanism is operatively related.

3. In a four-wheel brake system for motor cars, the combination, with the front and rear wheels and their individual brakes,,of hydraulic cylinder-and-piston mechanism, differential operating mechanism individual to the front and rear pairs of brakes, a lever system between the hydraulic mechanism and the two differential mechanisms, means for supplying pressure fluid to the hydraulie mechanism, a valve for control 'ng the fluid supply, a pedal for operati g said valve, and a hand lever operatively associated with said-lever system for actuatirfg the same to apply the rear brakes independently of the hydraulic mechanism and to the exclusion of the front brakes; substantially as described. 1

4. A four-wheel brake "system according to claim 3, in which the connegtions be-, tween the hand lever and the lever system include a lost-motion device which permits the lever system to be operated by the hydraulic mechanism while the hand lever re mains stationar substantiallyaas described.

5. In a four-wheel brake system for motor cars, the combination, with the front and rear wheels and their individual brakes, of

front and rear-differential operating mecha- .nisms connected with the front and rear pairs of brakes, hydraulic cylinder-andpiston mechanism, a differential mechanism separate from the two first-named difierential mechanisms but connected to operate both of them, and means for automatically operating the last-named differential mechanlsm from. the'hydraulic mechanism; substantially as described.

6. In a four-wheel brake system for motor cars, the combination, with the front and rear wheels and their individual brakes, of

front and .rear differential operating mechaieo nisms connected with the front and rear pairs ofbrakes, hydraulic cylinder-andpiston mechanism, a differential mechanism separate'from the two first-named differen- 'tially as described.

7. In a four-wheel brake system for motor cars, the combination, with the front and reaswheels and their individual brakes, of

front andrear differential operating mechanisms connected with the front and rear pairs of brakes, hydraulic cylinder-andpiston mechanism, a differential mechanism separate from the two first-named differential mechanisms but connected to operate both of them',-means for automatically operating the last-named differential mechanism from the hydraulic mechanism, and manual means for operating the rear differential mechanism independently of said last-named differential mechanism, and to the exclusion of the front differential mechanism; sub stantially as described.

8. In a four-wheel brake system for motor ears, the combination, with the front and rear wheels and their individual brakes, of

nisms connected with the front and rear pairs of brakes, hydraulic cylinder-audpiston mechanism, a differential mechanism separate from the two first-named differential mechanisms but connected to operate both of them, a pedal for operating the lastnamed differential mechanism either directly or indirectly and automatically through the hydraulic mechanism, and-a.- lever for manually operating the rear differential mechanism independently of the pedal and to the exclusion of the front differential mechanism; substantially as described.

9. In a four-wheel brake system for motor cars, the combination, with the frontv and rear wheels and their individual brakes, of front and rear differential operating mechanisms connected with the front and rear pairs of brakes, hydraulic cylinder-audpiston mechanism, a differential mechanism separate from the two first-named differential .mechanisms but connected to operate both of them, means for operating the lastnamed differential mechanism either direct- -lv or indirectly and automatically through the hydraulic mechanism, and -meansfor operating one of the two first-named differential mechanisms independently of the.

hydraulic mechanism and to the exclusion o the other first namod differential mechanism; substantially as described.

10, Ina four-wheel brake system for motor cars, the. combination, with the front and rear wheels and their individual brakes, of front and rear differential operating mechanisms for the corresponding pairs of brakes,

. a third differential mechanism separate from the first two differential mechanisms but.

connected to operate both of them, and a single fluid-operated piston connected to directly operate the third'differential mechanism; substantially as described.

11. In a font-wheel brake system for motor cars, the con'ibination, with the front and rear wheels and their individual brakes, of front and rear differential operating mechanisms for the corresponding pairs of brakes,

a third differential mechanism separate from the first two differential mechanisms but connected to operate both hf them, a single fluid-operated piston conn cted to directly operate the third differential mechanism, a valve for controlling the supply of motive fluid to said piston, and a pedal for opening said valve to actuate the piston or for di- -reetly operating the third differential mechanism: substantially as described.

12. In a four-wheel brake system for motor cars, the combination, with the front and rear wheels and their individual brakes, of front and rear differential operating mechanisms for, the corresponding pairs of brakes, a third differential mechanism separate from the first two differential mechaf fi t 1d 'eflr d fferential operating meehanisms but connected to operate both of them,

a single fluid-operated piston connected to directly operate the third differential mechanism. and manual means for operating the rear differential mechanism independently of the third differential nieehanisu'i and to the 1 :lusion of'the front differential mechanism: substantially as described.

13. In a four-wheel brake system for n10- tor cars, the con'ibination, with the front and rear wheels and their individual brakes, of front and rear differential operating mechanisms for the corresponding pairs of brakes, a third differential mechanism separate from the first two differential mechanisms but connected to operate both of them. a single fluid-operated piston connected to directly operate the third differential lllOClitUllStfl, a valve for controlling the supply of motive fluid to said piston, a pedal for opening said valve to actuate the piston, or for directly operating the third differential mechanism, and manual means for operating the rear differential mechanism independently of the pedal and to the exclusion of the front differential mechanism; substantially asde-.

ing to the rear brakes to set the latter independently of the pedal and to the exclusion of the front brakes; substantially as described.

15. In a four-Wheel brake system for m0- tor cars, the combination, with the front and rear wheels and their brakes, of hydraulic cylinder-and-piston mechanism, connections between said mechanism and all of the brakes to actuate them simultaneously, a valve for controlling the supply of motive fluid to the hydraulic mechanism, a pedal connected to open said valve and operate the hydraulic mechanism or toy directly operate said brake-actuating connections, and ahand brakes and to enable said pedal to be shifted while the lever remains stationar substantlally as described.

In testimony whereof I aifix my signature.

GUIDO FORNACA. 

